Ketone derivatives of 1 4-benzodithian and 1 4-benzoxathian

ABSTRACT

5,6,7,8 - TETRAHYDRO - 8- OXO - 1,4 -BENZODITHIAN AND 5,6,7,8 - TETAHYDRO - 8 - OXO - 1,4 - BENSOXATHIAN ARE PREPARED BY BASE-CATALYZED REACTION OF 2- HALO - 2- CYCLOHEXEN - 1 - ONE OR 2,3-EPOXYCYCLOHEXANONE WITH A DIMERCAPTOALKANE OR A MERCAPTOALCOHOL. THEY ARE DEHYDROGENATED TO THE CORRESPONDING PHENOL AND CONVERTED TO NMETHYLCARBAMATES, WHICH HAVE INSECTICIDAL ACTIVITY.

United States Patent 3,636,047 KETONE DERIVATIVES 0F 1,4-BENZODITHIAN AND 1,4-BENZOXATHIAN Michel Tobias, Edison, N.J., assignor to Mobil Oil Corporation N0 Drawing. Filed Nov. 29, 1968, Ser. No. 780,185 Int. Cl. C07d 13/00, 89/14 US. Cl. 260-327 P 4 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION Field of the invention This invention is directed to condensed ring heterocyclic compounds. It is more particularly concerned with ketones, phenols, and carbarnates of 1,4-benzodithian and 1,4-benzoxathian and the use of the carbamates as biocides.

Description of the prior art Insofar as is now known, the compounds of this invention have not been described in the prior art.

SUMMARY OF THE INVENTION This invention provides 5,6,7,8 tetrahydro 8 oxo- 1,4 benzodithians and 5,6,7,8 tetrahydro 8 oxo- 1,4 benzoxathians and their corresponding phenols and N-methylcarbamates thereof having the formulae:

H V V r I 6 43am 6 4 -11" Y Y wherein Y is O or S; R, R, R", and R' are hydrogen, methyl, or ethyl; and M is hydrogen or This invention also provides a process for producing the 5,6,7,8 tetrahydro 8 0x0 1,4 benzodithians and the 5,6,7,8 tetrahydro 8 oxo 1,4 benzoxathians that comprises reacting 2,3 epoxycyclohexanone, 2- bromo 2 cyclohexen l one, or 2 chloro 2 cyclohexen 1 one with a thiol having the formula:

wherein Y, R, R, R", and R' are as aforedefined, in the presence of a basic catalyst.

This invention further provides a method for controlling insects that comprises contacting them with at least one of the aforedescribed N-methylcarbamates and an insecticidal composition comprising at least one of the aforedescribed N-methylcarbamates and a carrier thereof.

3,636,047 Patented Jan. 18, 1972 DESCRIPTION OF SPECIFIC EMBODIMENTS The 5,6,7,8 tetrahydro 8 oxo 1,4 benzodithians and 5,6,7,8 tetrahydro 8 oxo 1,4 benzoxathians of this invention are readily prepared by the base-catalyzed reaction of 2,3-epoxycyclohexanone or of 2-brom0- (or 2-chloro-) 2 cyclohexen 1 one with an alkanedithiol or a mercaptoalcohol. The cyclic ketone reactants can be prepared by any of the methods fully described in the literature.

2,3-epoxycyclohexanone is produced by reacting 2- cyclohexen 1 one with hydrogen peroxide, such as described in J. Prackt. Chem, 111, 373 (1925). 2-chloro- 2-cyclohexen-l-one can be produced by adding chlorine across the double bond to give 2,3-dich1orocyclohexanone, followed by dehydrochlorination to yield the 2-chloro-2- cyclohexen-l-one. Similarly, using bromine instead of chlorine, the 2-bromo-2-cyclohexen-l-one can be prepared.

The thiol reactants, as used herein, are alkanedithiols and mercaptoalcohols (mercaptoalkanols) in which the two thiol groups or the mercapto and hydroxyl groups are on adjacent carbon atoms of an alkane. The alkanedithiols are readily prepared by reacting the corresponding dichloroor dibromoalkane with sodium mercaptide. Typical alkanedithiols are ethanedithiol; propanedithiol; 1,2- butanedithiol; 2,3-butanedithiol; 2,3-dimethyl-2,3-butanedithiol; 2 ethyl 1,2 butanedithiol; 2,3 pentanedithiol; and 3,4-hexanedithiol.

The mercaptoalkanols can be prepared by methods well known in the art and many are commercially available. Typical mercaptoalkanols are mercaptoethanol; 2-mercaptol-propanol; and l-mercapto-Z-butanol; 2-mercapto- 2-butanol.

As mentioned hereinbefore, the reaction between the cyclic ketone reactant and the thiol reactant is carried out in the presence of a basic catalyst. Suitable catalysts include inorganic bases, such as sodium hydroxide and potassium hydroxide; amines, such as triethylamine and organic bases, such as benzyltrimethylammonium methoxide, benzyltrimethylammonium hydroxide, and sodium alkoxide.

The reaction is preferably carried out in polar solvents, such as methanol, dimethoxymethane, acetonitrile, and chloroform. Preferably, a solution of an equimolar mixture of the reactants is slowly added to a solution of the catalyst. The reaction is exothermic and temperature should be controlled to about 50 C. or lower. Typical manipulations and product isolation techniques are demonstrated in the specific working examples.

Non-limiting examples of the compounds produced as aforedescribed are 5,6,7,8-tetrahydro-8-oxo-1,4-benzodithian; 5,6,7,8-tetrahydro-2-methyl-8-oxo-1,4-benzodithian; 5,6,7,8-tetrahydro-3-methyl-8-oxo-1,4-benzodithian; 5,6,7,8-tetrahydro-2-ethyl-8-oxo-1,4-benzodithian; 5,6,7,8-tetrahydro-3-ethyl-8-oxo-1,4-benzodithian; 5,6,7,8-tetrahydro-2,2-dimethyl-8-oxo-1,4-benzodithian; 5,6,7,8-tetrahydro-2-ethyl-3-methyl-8-oxo-1,4-

benzodithian; 5,6,7,8-tetrahydro-2,2,3,3-tetramethyl-8-oxo-1,4-

benzodithian; 5 ,6,7,8-tetrahydro-8-oxol ,4-benzoxathian; 5,6,7,8-tetrahydro-2-methyl-8-oxo-1,4-benzoxathian; 5,6,7,8-tetrahydro-3-methyl-8-oxo-1,4-benzoxathian; 5,6,7,8-tetrahydro-Z-ethyl-8-oxo-1,4-benzoxathian; 5,6,7,8-tetrahydro-3-ethyl-8-oxo-1,4-benzoxathian; 5 ,6,7,8-tetrahydro-3 ,3 ,-dimethyl-8-oxo-1,4-benzoxathian; 5 ,6,7,8-tetrahydro-2-methyl-3-ethyl-8-oxo-1,4-

benzoxathian; and 5,6,7,8-tetrahydro-2,2,3,3-tetramethyl-8-oxo-1,4-

benzoxathian.

3 The aforedescribed oxo compounds can be converted to the hydroxy (phenol) derivative by dehydrogenation in the liquid or vapor phase, using methods well known in the art. The procedure described in U.S. Pat. No. 3,317,552, was found efiective.

Non-limiting examples of the hydroxy derivatives of the aforedescribed oxo compounds are:

8-hydroxyl ,4 benzodithian; Z-methyl-S-hydroxy-1,4-benzodithian; 3-methyl-8-hydroxy-1 ,4-benzodithian; 2-ethyl-8-hydroxy-1,4-benzodithian; 3-ethyl-8-hydroxy-1,4-benzodithian; 2,2-dimethyl-8-hydroxy-1,4-benzodithian; 2-ethyl-3-methyl-8-hydroxy-1,4-benzodithian; 2,2,3,3-tetramethyl-8-hydroxy-1,4-benzodithian; 8-hydroxy-1 ,4-benzoxathian; 2-methyl-8-hydroxy- 1,4-benzoxathian; 2-ethyl-8-hydroxy-1,4-benzoxathian; 3-ethyl-8-hydroxy-1,4-benzoxathian; 3,3-dimethyl-8-hydroxy-1,4-b enzoxathian; and 2,2, 3 ,3-tetramethyl- S-hydroxy- 1 ,4-benzox athian; S-hydroxy-1,4-benzoxathian; 2-methyl-8-hydroxy- 1 ,4-benzxathi an; 3-methyl-8-hyd roxy- 1 ,4-benzoxathian; 2-ethyl-8-hydroxyl ,4-benzoxathian; 3-ethyl-8-hydroxy-1,4-benzoxathian; 3,3-dimethyl-8-hydroxy-1,4-benzoxathian; 2-methyl-3-ethyl-S-hydroxy-1,4-benzoxathian; and 2,2,3 3-tetramethyl- 8-hydroxy- 1,4-benzoxathian.

The insecticidal carbamates of this invention are prepared by any of the well 'known methods for converting hydroxy compounds to carbamates. A feasible procedure is to react the hydroxy compound with methyl isocyanate. Another procedure is to react the hydroxy compound with phosgene to form a chloroformate which is then reacted with methylamine. These procedures and the conditions involved can be found in 15.8. Pats. Nos. 3,288,673 and 3,288,808.

Non-limiting examples of the insecticidal carbamates of the aforedescribed hydroxy compounds are:

The N-methylcarbamates of this invention have been found to exhibit considerable biological activity and are potent insecticides when used against important agricultural pests. These compounds may be used in various ways to achieve biological action. They can be applied per se, as solids or in vaporized form, but are preferably applied as the toxic components in pesticidal compositions of the compound and a carrier. The compositions can be applied as dusts, as liquid sprays, or as gas-propelled sprays and can contain, in addition to a carrier, additives such as emulsifying agents, wetting agents, binding agents, gases compressed to the liquid state, odorants, stabilizers, and the like. A wide variety of liquid and solid carriers can be used in the pesticidal compositions. Non-limiting examples of liquid carriers include water; organic solvents such as alcohols, ketones, amides, esters; mineral oils such as kerosene, light oils, medium oils; and vegetable oils such as cottonseed oil. Non-limiting examples of solid carriers include talc, bentonite, diatomaceous earth, pyrophyllite, fullers earth, gypsum, flours derived from cotton seeds and nut shells, and various natural and synthetic clays having a pH not exceeding about 9.5.

The amount of the N-methylcarbamate compounds of this invention utilized in pesticidal compositions will vary rather widely. It depends to some extent upon the type of composition in which the material is being used, the nature of the condition to be controlled, and the method of application (i.e., spraying, dusting, etc.). In the ultimate pesticidal composition, as applied in the field, pesticide concentrations as low as 0.0001 weight percent of the total composition can be used. In general, compositions, as applied, containing about 0.05 weight percent pesticide in either liquid or solid carrier give excellent results. In some cases, however, stronger dosages up to about 10 weight percent may be required.

In practice, pesticidal compositions are usually prepared in the form of concentrates, which are diluted in the field to the concentration desired for application. For example, the concentrate can be a wettable powder containing large amounts of a compound of this invention, a carrier (e.g., attapulgite or other clay), and wetting and dispersing agents. Such powders can be diluted prior to application, by dispersing in water to obtain a sprayable suspension containing the concentration of pesticide desired for application. Other concentrates can be solutions that can be later diluted, e.g., with kerosene. Thus, it is within the contemplation of this invention to provide pesticidal compositions containing up to about percent, by weight of the composition, of a pesticidal compound of this invention. Accordingly, depending upon whether it is ready for application or it is in concentrated form, the contemplated pesticidal compositions contain about between 0.0001 percent and about 80 percent, by weight of the composition, of a pesticidal compound of this invention and a carrier, liquid or solid, as defined hereinbefore.

EXAMPLE 1 Five and six-tenths gram (0.05 mole) of 2,3-epoxycyclohexanone and 4.7 g. (0.05 mole) of 1,2-ethanedithiol were each placed in 5 ml. of methanol and added dropwise to a solution of 5 drops of 15% sodium hydroxide, 20 ml. of dimethoxyethane and 5 ml. of methanol. Addition was completed in 30 minutes, while the temperature of the reaction was maintained at 50 C. After standing for 36 hours at room temperature, 7.6 g. of 5,-6,7,8-tetrahydro- 8-oxo-l,4-benzodithian was filtered from the reaction, M.P. 183-185 C. after several recrystallizations from acetone.

EXAMPLE 2 Seven grams (0.037 mole) of 5,6,7,8-tetrahydro-8-oxo- 1,4-benzodithian, 2.4 g. (0.074 mole) of sulfur and 60 ml. of diphenyl ether were heated together at 245-255 C. for 2 hours. After cooling, the reaction mixture was diluted With ether and then extracted with dilute sodium hydroxide solution. Acidification of the basic extracts yielded 7.0 g. of dark oil which upon distillation yielded 2.7 g. of 8-hydroxy-1,4-benzodithian, B.P. 134-137 (2 mm). The phenol slowly crystallized upon standing to a yellow solid, M.P. 59-63 C.

EXAMPLE 3 Two and two-tenths grams (0.012 mole) of 8-hydroxy- 1,4-benzodithian and 1.1 g. (0.02 mole) of methyl isocyanate were placed in 20 ml. of benzene containing 2 drops of dibutyltin diacetate, and allowed to stand for 5 days at room temperature. Addition of petroleum ether to the benzene solution precipitated 2.2 g. of 8-( 1,4-benzodithianyl)-N-methylcarbamate, M.P. l25135 C. after 1 recrystallization from ethyl acetate.

EXAMPLE 4 hydroxy-l,4-benzodithian and 0.8 g. of (0.014 mole) of methyl isocyanate were placed in 15 ml. of benzene containing 2 drops of dibutyltin diacetate and allowed to stand for 4 /2 days at room temperature. Dilution of the 5 benzene solution yielded 1.2 g. of 2-ethyl-8-(l,4-benzo- Five and Sixtenths grams 111016) of -P YY dithianyl)-N-rnethylcarbamate, which failed to crystallize hexanone and 3.9 g. (0.05 mole) of 2-mercaptoethanol on t di were each placed in 5 ml. of dirncthoxyethane and added Th compounds f E l 3, 6, d 9 were bj d dropwise to 25 1111- Of acetonitrile Containing 6 drops of to the following insecticide tests. The results were set a 40% methanolic solutio of nzyl rim y mm ni 10 forth in the table as percent control at 500 p.p.m., folmethoxide. The temperature of the exothermic reaction lowing th t t d i ti was not allowed to rise above 45 C. After standing overnight at room temperature, the solvent was removed at INSECTICIDE TESTING METHODS reduced pressure. Distillation of the residue yielded 5.9 g. Dip test of an 129-1340 (2 which Slowly crystal- Mexican bean beet-le' Epilachna va rivestis Mu1santhzed l i f upon Lima bean leaves of uniform size are momentarily dipped Standmg 106-108 after recrystalhzatlon from in a 500 p.p.m. water-acetone solution of the test competroleum etherthen pound. When dry, the treated leaf is placed in a screened EXAMPLE 5 petri dish and exposed to 10 fourth instar larvae. The Five and five tenths grams (0.032 mole) of 567,8 percent morgilityhis recorded after forty-eight hours. tetrahydro-8-oxo-1,4-benzoxathian, 2.05 g. (0.064 mole) commziunds CW 90 percent or more mortahty are of sulfur and 60 ml. of diphenyl ether were heated toretgstehatl an gether at 245-255 C. for 3 hours. At this point the rei t E w t m g g i? action mixture was worked-up in the same manner as b 15 G a i escnie or b p t: was described in Example 2. Distillation of the crude ean usmg 01m mstar arvae an O reaction products yielded 0.8 g. of 8-hydroxy-1,4-benzoxmorta my after 48 h athian BR C (2 Two-spotted spider mite: T etranychus telarius Linnaeus.--Infested trifoliate bean leaves (Henderson bush EXAMPLE 6 lims) are selected that have as many as twenty adult mites Eight tenths gram (0005 mole) of 8 hydrOXy 1,4 per leaf. Leaves with mites attached are momentarily benzoxathian and 085 ((1015 mole) of methyl dipped into a 500 p.p.m. emulsion, SOIUUOH, or suspension cyanate were placed in 10 ml. of benzene containing 2 of the test Compounds and then Placed (Pfitlole only) m f drops of dibutyltin diacetate, and allowed t t d at room 4 oz. bottle of water for observation. Percent mortal ty s temperature for 3 /2 days. Dilution of the benzene solution Observed after 72 hours- If 90400 Percent mortallty with petroleum ether yielded 1.0 g. of 8-(1,4-benzoxathi- Observed compounds are retested at and 10 anyl)-N-me thylcarbamate, which failed to crystallize Spray t t upon standmg' EXAMPLE 7 Housefly: Musca domestica Linnaeus.Adult houseflies are contained in 100 mm. petri dish screened cages FOUIte'eH and four-tenths grams mole) of and exposed to a spray of 10 ml. acetone solution of test mo-z-cyclohexefl-l-one and -gmole) of compound. An initial concentration of 500 p.p.m. is used, butalledithiol Were each Placed in 15 Of chlmoform with ten flies in each cage. Percent mortality is observed and added dropwise to 70 ml. of chloroform containing ft 24 hours w over 90 percent mortality is H1016) 0f tfiethylamil'le- The Simultaneous served, the compound is retested at the lower concentraaddition of reactants was complete in 80 minutes. The i temperature of the exothermic reaction was not allowed to B hid; A hi f b Thi t i d t d i a rise above After Standing Overnight at ambient manner similar to that used for the housefly. The test temperature, the reaction miXtlll'e heated at reflux specimens are nasturtium leaves infested with bean for 3 hours. After cooling, the reaction mixture was hid Washed With Water, Saturated brine, and dried over Boll Weevil: Anthonomus Grandis.This test is connesillm Sulphate- Distillation yielded of 5- ducted in a manner similar to that used for the housefly. tetfahydfo-z-ethyl-s-om-1,4-be11Z0dithian, The test specimens are ten boll weevils per screened petri C. (0.03 mm.). dish.

EXAMPLE 8 Mosquito larvae: Aedes aegypti Linnaeus.-Early Five and Sevemtenths grams (0027 mole) of 5,67,8 fourth stage larvae are exposed to solutions, emulsions tetrahydro-Z-ethyl-8-oxo-1,4-benzodithian, 1.75 g. of sulsuSPenSlOnF of the test compound In The fur (0054 mole) and of diphenyl ether were heated pounds are dissolved in acetone and added to ars of distogether at 245-255 C. for 2.5 hours. The reaction was fined Water F f larvae' water'soluble worked-up in the same manner as described in Example 60 PPQ rema1n sob-Hons and fibers form finely Distillation yielded 17 of h l g h d 4 divided suspensions. Compounds are initially tested at one benzodithian, 137439 (2 p.p.m. using ten larvae per 100 ml. water. Percent of mortality is observed after 24 hours. If 100 percent EXAMPLE 9 mortality occurs, compounds are retested at 0.1 and 0.01 One and two-tenths grams (0.006 mole) of 2-ethyl-8- p.p.m. Results are reported: p.p.m. cone/percent kill.

TABLE Mexican Compound bean Southern Spider House- Bean Boll Mosquito of Example beetle armyworm mite fly aphid Weevil larvae $8 43 38 8 138 188 l88 9 60 0 30 0 0 100 Although the present invention has been described with preferred embodiments, it is to be understood that modifications and variations may be resorted to, without departing from the spirit and scope of this invention as those skilled in the art will readily understand. Such variations and modifications are considered to be within the purview and scope of the appended claims.

What is claimed is:

1. 5,6,7,B-tetrahydro-S-oxo-1,4-benzodithian and 5,6,7, S-tetrahydro-S-oxo-l,4-benzoxathian having the formuia:

wherein Y is O or S; R, R, R", and R are hydrogen, methyl, or ethyl.

2. 5,6,7,8-tetrahydro-8-oxo-1,4-benzodithian.

3,455,912 7/1969 Eitel et a1 260340.3 3,185,692 5/1965 Judd 260-268 2,864,826 12/1958 Diveley 260327 OTHER REFERENCES Lowy, et al.: Int. Org. Chem, New York, 1945, pp. 213-5.

Reid: Org. Chem. of Bivalent S, Chem. Pub. C0., New York, 1960, vol. II, pp. 35, 36, 212-9.

HENRY R. JILES, Primary Examiner C. M. SHURKO, Assistant Examiner US. Cl. X.R. 424276, 277

(5/69) li STATES PATENT FFEE Patent No. Dated January 18, 197

Inventor) Michael A. Tobias It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line LO, should be Column 7, line l3-l5,

Should be Y Signed and sealed this 29th day of August 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents 

